Supply chain consultant here. I have been involved as an expert witness in several force majeure disputes since 2020 and the case law has evolved significantly. Here are some observations that might help.
Post-pandemic, courts are much more skeptical of force majeure claims. The reasoning is that after COVID, supply chain disruptions and labor shortages are foreseeable risks that businesses should have planned for. Many recent court decisions have rejected force majeure defenses where the claimed event was something the party could have anticipated and mitigated.
One important development: several courts have held that increased costs alone do not constitute force majeure. The other party needs to show that performance was truly impossible or impracticable, not just more expensive than anticipated. If they can still perform but it would cut into their margins, that is typically a commercial impracticability argument (which has an even higher bar) rather than force majeure.
Request documentation from the other party. Ask them to provide specific evidence of the force majeure event, how it directly prevented their performance, what mitigation steps they took, and when they first became aware of the issue. If they cannot provide concrete answers to these questions, their claim is likely weak.